[llvm-commits] [llvm] r56267 - in /llvm/trunk: lib/Target/PowerPC/PPCISelLowering.cpp lib/Target/PowerPC/PPCISelLowering.h test/CodeGen/PowerPC/trampoline.ll

[Chris Lattner]

On Sep 17, 2008, at 12:34 PM, Bill Wendling wrote:

> On Tue, Sep 16, 2008 at 11:28 PM, Duncan Sands <baldrick at free.fr>  
> wrote:
>> Hi Bill,
>>
>>> Add trampoline support to PPC. GCC simply calls the  
>>> "__trampoline_setup"
>>> function with appropriate parameters. This allows us to support  
>>> blocks on PPC.
>>
>> glad to see trampolines coming in useful!  I was surprised to see
>> this though: I thought the whole point of blocks is that it doesn't
>> need trampolines...
>>
> It might be an implementation detail for PPC. I need to check with the
> person who implemented it in our GCC branch to see if this was
> intentional...

This was a bug that has already been fixed in the apple gcc, we just  
haven't merged in the fix yet.  Blocks are implemented internally with  
the same GCC machinery that nested functions use, but trampolines  
should never ever be generated.

-Chris